The present invention relates in general to document feeders for reproduction apparatus, and more particularly to a document feeder which is automatically loaded or unloaded with a stack of document sheets to be copied.
Typical commercially available reproduction apparatus are capable of making reproductions at a significant rate (in excess of one hundred copies per minute). Such high reproduction rates are possible, at least in pan, due to document feeders which automatically present document sheets to an exposure station for the reproduction apparatus. Several examples of document feeders enabling high reproduction rates are respectively found in U.S. Pat. No. 4,699,365 (issued Oct. 13, 1987, in the name of Smith et al) and U.S. Pat. No. 5,076,560 (issued Dec. 31, 1991, in the name of Russel).
The exemplary document feeders as shown in the above mentioned U.S. patents, along with most other document feeders, accept a document set stack in a hopper (or some type of receptacle). Individual document sheets are delivered from the stack seriatim to the exposure station or scanner for the reproduction apparatus and then returned in order to the hopper. The desired number of reproductions of the document set stack is made by circulating the individual document sheets one-at-a-time from the hopper to the exposure station, making the desired number of reproductions of each sheet, and then from the exposure station back to the hopper; alternatively, the desired number of reproductions of the document set stack is made by recirculating the individual document sheets from the hopper to the exposure station and then back to the hopper a number of times equal to the desired number of reproductions, with one full reproduction of the document sheet stack being made on each circulation.
While document feeders of the described type have proven to be the most efficient in providing high reproduction rates for reproduction apparatus, one must be able to place the document sheet set stack in the hopper of the document feeder. Ordinarily, this does not present a problem. However, since the document feeders are located on the top of the reproduction apparatus, there are certain physically challenged individuals who cannot reach the hopper to place the document sheet set stack therein. This may be due to the height of the individual or to some disability or impairment. For example, someone confined to a wheel chair may not be able to reach the hopper of the document feeder. This would severely limit the ability of this person to use the reproduction apparatus to the fullest capacity. That is, the reproduction apparatus could only be used in the mode where individual document sheets are manually placed on the exposure station, a process which the document feeder was meant to replace for the increased productivity.